A comparison of skinfold thickness measurements and dual-energy x-ray absorptiometry analysis of percent body fat in football players

Abstract

OBJECTIVE The method of Dual-Energy X-ray Absorptiometry (DEXA) is considered to be the ‘gold standard’ for the measurement of bone density and body composition. Skinfold thickness is a commonly used technique for assessing percent body fat, where accuracy depends on the prediction equation being specific to the population assessed. Results of skinfold measurements are occasionally interchanged with those of DEXA for convenience. The purpose of this study was to check the validity of skinfold thickness measurements by callipers as opposed to DEXA, in predicting percent body fat (%BF) in male elite English Premier League football players, and to establish a new prediction equation based upon skinfolds to estimate %BF. METHODS Players from one Premiership football squad (N = 28; 81.94 ± 9.16 kg; 1.82 ± 0.06 m; 24.1 ± 5.4 years) %BF were assessed using DEXA, and skinfolds of triceps, subscapular, biceps, iliac crest, supraspinale, abdominal, front thigh and medial calf (Withers et al., 1998). Paired t-test and correlation coefficient were used to assess the relationship between the methods; linear regression was used to create new prediction equations. RESULTS Values for %BF were: DEXA- 11.53 ± 1.61 % and skinfold- 11.20 ± 2.53 %. There was no difference in the players’ % BF between the two methods (P > 0.05), which were highly correlated (r = 0.700; P < 0.001). A regression equation specific to elite male football was generated using 8 skinfolds (Equation 1), mean % BF being 11.52 ± 1.22 % (r = 0.762). Equation 1: Fat % = (0.161 x triceps) – (0.033 x subscapular) – (0.005 x biceps) + 0.175 x iliac crest) – (0.123 x supraspinale) + (0.046 x abdominal) + (0.023 x front thigh) + (0.162 x medial calf) + 6.692 DISCUSSION The assessment of %BF can be estimated by skinfolds using the formula of Withers et al. (1998) The novel prediction equation increased the correlation and reduced the TEM, CV% and total absolute difference of %BF, improving accuracy in predicting %BF from skinfolds. In a future study the unexplained variants on repeated use of skinfolds shall be studied in this elite football population. REFERENCES